Stents and stent delivery assemblies are utilized in a number of medical procedures and situations, and as such they are well known and widely available in a variety of designs and configurations. A stent is a generally cylindrical prosthesis introduced via a catheter into a lumen of a body vessel in a configuration having a generally reduced diameter and then expanded to the diameter of the vessel. In its expanded configuration, the stent supports and reinforces the vessel walls or, e.g., cardiac valve, while maintaining the vessel in an open, unobstructed condition.
Inflation-expandable stents are well known. Inflation-expandable stents are crimped to their reduced diameter about the delivery catheter, then maneuvered to the deployment site and expanded to the vessel diameter by fluid inflation of a balloon positioned between the stent and the delivery catheter. Alternatively, the stent is a self-expanding stent that acts similarly to a spring and will recover to its expanded or implanted configuration after being released from a compacted condition such as in a sheath. A self-expanding stent has a radially and axially flexible, elastic tubular body with a predetermined diameter that is variable under axial movement of ends of the body relative to each other and which is composed of a plurality of individually rigid but flexible and elastic thread elements defining a radially self-expanding helix. Self-expanding stents can use alloys such as Nitinol (i.e., Ni—Ti alloy) which have shape memory and/or superelastic characteristics in medical devices which are designed to be inserted into a patient's body. The shape memory characteristics allow the devices to be deformed to facilitate their insertion into a body lumen or cavity and then be heated within the body so that the device returns to its original shape. Placement of such stents in a body vessel can be achieved by a device which comprises an outer catheter for holding the stent in its compact form.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.